Understanding the neural regulation of behavioral arousal and motor facilitation is important in understanding the normal control of sleep- wake regulation and control of motor output, as well as elucidating the basis of such clinically relevant conditions as insomnia, excessive day time sleepiness, rapid-eye movement behavior disorder and narcolepsy. Consequently, the broad, long-term objective of this research program is to understand the role of the posterior hypothalamus in the production of cortical and behavioral arousal. The experiments included in this proposal are designed to determine whether the posterior hypothalamus is necessary for the production of the behavioral components of wakefulness and whether initiation of limb movements by this region of the brain is a result of promotion of a generalized arousal in the animal. The experiments included in this proposal are designed to test the hypotheses that: 1) rats transected in such a fashion as to leave the basal diencephalon and brainstem intact continue to cycle through sleep-wake states., 2) the limb movements exhibited by these animals are clustered in wakefulness., 3) there is a circadian influence on the expression of the limb movements., 4) removal of the posterior hypothalamus completely eliminates these limb movements., 5) electrical microstimulation in the posterior hypothalamus produces generalized arousal followed by expression of limb movements. A secondary objective of this proposal is to introduce undergraduate and Masters level graduate students to biomedical research. Consequently, the experiments have been designed to allow substantial student involvement. The research proposed will introduce students to the clinically important field of sleep research, as well as basic neurophysiological techniques. For example, the students will learn small animal stereotaxic surgery, electrical microstimulation, electrophysiological recording and brain histology/ lesioning. These techniques are widely applicable to many questions in the neurosciences. The students will also receive training in basic experimental design, reduction and statistical analysis of data, and manuscript and seminar preparation. These techniques and skills will provide a sound base for and stimulate interest in more advanced training in the biomedical sciences.